Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Bnine on May 30, 2011, 05:38:15 PM
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http://www.cbc.ca/news/canada/british-columbia/story/2011/05/16/bc-dodgeproblem.html
Some of you may have seen this on the news.
An article that helps explain what dodges issue is with death wobble.
While the following article doesnt really explain anything technically, it brings to light a major point that several of us in the jeep world have been making for a few years now.
Jeep and dodge truck control arm bushings are to soft/weak from the factory.
This is why you are seeing more and more none modified, almost new vehicles experiencing DW. The factory bushings simply arent strong enough to hold things in checkl.
Thats also why you are seeing more stock jks with DW then you ever did TJ's. Jeep didnt not change their bushing design when they did the jk's. What they did though was increase both tire and rim sizes and weights, subsequently subjecting the front end to more stress then what the TJ's had, resulting in more cases of death wobble.
The only thing jeep did to counter the increased weight on the jks was add a beefier stabilizer, which does make a slight difference, but also means most jks get death wobble at the first sign of a worn stabilizer.
Also, when jeep changed the tie rod to a knuckle to knuckle type instead of the old inverted Y style, it increased the likelyhook of death wobble. A direct connection from knuckle to knuckle allows the tires to get into harmonics a bit easier then the Y style.
For anyone who has played with this at one time or another, your best bet is to upgrade your control arm bushings. That will tighten up the front end and not allow it to move so easily. The front end has to move in order for death wobble to initiate. Anything else is just a tire shimmy. You can not get death wobble without axle movement.
The best joint to use is the currie johnny joint. Avoid poly bushings at all cost. They ride poorly, and wear fast. Avoid JKS arms, they use stock TJ bushings. You are just trading one evil for another at 400$ a pair. Avoid RE arms because nowadays they just suck compared to whats available this day and age.
When you are helping friends, always talk about the bushings. As soon as you modify a jeep with shallow back spacing, heavy rims, and big tires, you risk death wobble. Addressing with anything other then stiffening the front end to handle the modifications that have been made is pure gambling.
Essentially there is no free lunch.
This should help you guys for the next half a dozen or so death wobble cases that show up.
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this is good to know .. alot of dodge owners just raise there trucks and slap on 37"s with out changing anything at all
let hope they can get this issue under control befor they band over size tires on jeeps
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Interesting article but the "engineer" did not really have anything enlightening to say either ::)
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They never do. They know whats wrong, but its a cost versus risk scenario. To date, there hasnt been enough incidents to warrant the cost of addressing the issue.
They'll never come out and admit publicly whats wrong until after they are forced to correct it.
Even then, you'll here two years later that they changed the durometer in their bushings from something like 60-65 and thats why the frequency has gone down.
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Excellent post, a lot of good info in there. Another thing to mention is most "cheaper" kits have terrible track bar brackets, bushings and poorly fitting crush sleeves. As this is the piece that centers your axle under the jeep it's worth spending the extra bucks to get quality well fitting stuff.
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It's surprising to me how this is "News".
As a Dodge truck owner, I did my research before buying my 2003 3/4 ton Cummins.
A) Front end notoriously weak, balljoints, bushing, tierod ends, pinion bearing+seal.
B) Steering box issues - Due to steering setup, angle of steering box+pitman arm. Sector shaft in steering box takes a beating. The fix - http://www.solidsteel.biz/dss.htm
C) In the 03-04 range, 5.9L HPCR engines, the lift pump was a large POS when attached to the fuel filter housing, Recall was issued, and lift pump relocated to in-tank sender which is just slightly less a POS compared to the original.
D) In the 03-04 range, best fuel economy out of 5.9L CR Cummins motors, lower HP, but incredible fuel mileage. (Mine, with power upgrades, and 22" Wheels, still gets between 9-11L/100Km unloaded depending on how heavy my right foot is, Loaded is 14L/100Km. Eat your heart out 6.7 owners!)
As mentioned before, lifts and tires compound already weak issues.
Primary reason for DW, worn parts, and LOM (Lack Of Maintenance). Plus owners, or dealer techs, only installing cheaper or dealer recommended parts. Thus extending the issue.
From the Jeep world, we know to replace parts with Bigger/Better/Badder, thus eventually solving our DW issues.
This "News" is simply out of touch, uneducated owners dealing with the economies of scale.
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I had this problem on my 2005 2500HD, also caused snapping and binding like someone was beating on the frame with a sledge whenever I was backing and turning at the same time - also scary as hell sway with the camper on the back - luckily I only bought the truck 6 months a go so the dealer fixed it and checked all the controll arm bushings and ball joints at the same time no cost to me.
When I first found the problem I measured 2" side to side movement on the bolt in the upper bushing on a drive pavement steer test and was first told by the dealer service mgr on the phone that that much play was normal - I pushed the issue with the salesman when he made a follow-up call hence the comment above and the problem solved for now
Of course I consider the solution temporary as the same bar and bushing are still there - Its very frustrating that the bushing is none seviceable and their only solution to further wear potential was to buy a whole new trackbar as the bushing is molded in.
So Bnine, would you reccomend making a custom trackbar with a johnny joint on the frame side, should I have any concern about no give or freeplay in that type of set-up or do you know if an aftermarket product is available that I should be looking at. I didn't have any plans to lift this truck as it is the hauler and camper. Is that a component you would be interested in fabricating ?
Thanks
Rob
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I had the DW on an RE 4" lift and 35's. I have installed a currie trackbar. I was going to test drive it without a steering stabilizer and if the problem is solved I'll put in the new stabilizer. If not, then I'm thinking I'll get currie lower adjustable control arms. and test it again. Does this make sense?
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Buying quality components is probably a whole other topic that could be dicussed to death on most boards. But yes, a good track bar is a must.
The currie hd with the 1/2" axle bolt and 5/8" frame bolt is the best off the shelf option I know of.